#include <iostream>
using namespace std;
typedef long long LL;

LL qmi(int a, int b, int p)
{
    LL res = 1;
    while (b)
    {
        if (b & 1)
            res = res * a % p;
        a = (LL)a * a % p;
        b >>= 1;
    }
    return res;
}

int main()
{
    int n;
    cin >> n;
    while (n--)
    {
        int a, p;
        cin >> a >> p;
        if (a % p == 0)
            puts("impossible");
        else
            cout << qmi(a, p - 2, p) << endl;
    }
    return 0;
}
\